The invention is concerned with a warp knitting machine having movable cable guides on an oscillating guide bar.
Such a warp knitting machine is known from U.S. Pat. No. 5,241,842. An object of the invention is to keep at a minimum the mass moving with the oscillations of a guide bar.
This object is achieved by the characteristics as recited in the following detailed description and in the claims.
The arrangement of cable guides on a carrier which only follows the basic shift movement of a guide bar results in that each cable guide does not participate in the oscillations of the corresponding guide bar or move therewith and, therefore, does not influence the oscillations with its own mass. This is beneficial for the speed of the movements of the guide bar. Because of arranging the cable guides at a relative great distance from the thread guides, a movement of the pull control cables, because of the oscillating movements of the thread guides, will change the deviation angle of the pull control cables very little so that the corresponding extent of movement can be compared with a very short sector of a circle having a large radius.
The measured length between a thread guide and its corresponding cable guide, during an oscillating movement, practically does not change, so that because of the oscillations of the thread guide, a pattern shift movement of the pull control cables does not appear.
Furthermore, a loosening up of the layout of the cable guides results in a corresponding flexible and easily followed further guidance of the pull control cables to the individual control motors which enhances any addition of a larger number of motors.
The cable guides are advantageously in the form of direction changing or deflection rollers.
Preferably, the pull control cables are each under the influence of a spring tension. The spring tension effectively should influence the pull control cable on both of its ends so that during a pattern shift movement cycle, a middle position is being assumed. The pull springs assume a state of equilibrium from which the control motors can adjust the pull control cables in a to- and fro- motion or mode for which very little energy is required because of a small adjustment magnitude, namely, such that a pull on the pull springs barely disturbs the above mentioned equilibrium.
Each of the pull control cables, preferably, is guided over a pretensioned tension roller being provided between a cable guide and a control motor. The tension roller is under the influence of the pull springs by being pulled against an adjustable abutment. By means of the adjustable abutment, a subsequent fine tuning of a corresponding pull control cable and a thread guide connected thereto can be achieved, it is being assumed that the corresponding pull control cable is being connected to a control motor. In this case, the control motor, at least in its own effective sphere, holds onto the pull control cable, so that during a change in the abutment, the length of the pull control cable between the control motor and the thread guide can be varied negligibly. Thereby, a negligible tension is being exerted on the control motor which, however, with regard to the normally small adjustment range, can practically be ignored.
In the case of a manual hang-out of a guide bar and in order to leave the pull control cables unaffected in the area. of the cable guides and the control motors, a cable clamp can be provided in the area of a push rod for the guide bar being effective to hold the pull control cables. In this case, the array of pull control cables remains under tension between the cable clamp and the control motors, so that in this area, no entanglement of the pull control cables can occur.
In order to enable a complete removal of the guide bar, hook couplings are provided in the pull control cables, preferably, in the area extending between the cable clamp and the guide bar, the couplings constituting through connectors. In the event of a complete removal of the guide bar from the machine, the hook couplings are unhooked. Upon the reinstallation of the guide bar, the hook couplings are merely reconnected and the cable clamp is loosened, whereby the overall arrangement of the pull control cables is functional again.